1. Field of the Invention
The present invention generally relates to a production method and a production device of three-dimensional pattern, and more particularly, to a method and a production device of forming a three-dimensional pattern on a three-dimensional workpiece.
2. Description of Related Art
Currently, electronic devices such as notebook computers, mobile phones, or digital cameras mostly adopt metal material for constituting the exterior. In order to advance the overall aesthetic appearance of electronic devices, various patterns are usually formed on the appealing configuration.
Patterns are produced on the surface of metal material frequently by etching metal material with a solvent or by paint-spraying and transfer printing. Nonetheless, the surface treatment technique of the former is complicated and difficult, and the production thereof is highly contaminative. The latter is restrained by the chemical property of metal material, such that artistic configuration cannot be produced. Taking the injection molding case made of magnesium alloy as an example, due to the high chemical activity of the alloy and the needs to perform lapping or repairing during the surface process, it is unable to make an original-color appearance with metallic sense on the workpiece surface.
If patterns are formed on a plastic casing, IMD (In Mold Decoration), such as IMR (In Mold Roller) or IMF (In Mold Film), is commonly used which bonds a decoration stack having patterns therein to the plastic casing by injection molding. However, the method requires high adhesion for each layer of the decoration stack so that shedding problem often arise in practice.